You can claim 2014 medical expenses credit for any 12 month period ending in 2014, so choose a window that encompasses as much expense as possible. Later than your end date, and you will claim them on 2015 taxes.
If you have a married or common law partner, consider claiming credit on the lower Net Income of the two, since there is a threshold below which no credit is given (3% of Net or $2161 whichever us the lower amount).
The dental expense you claim is for any amount not covered by insurance plans.
